Fireproofing textile materials



' Patented Sept. 28, 1943 FIREPROOFING TEXTILE MATERIALS William IvanTaylor, Henry Charles Olpin, and Kenneth Ronald House, Spondon, nearDerby, England, assignors to Celanese Corporation of America, acorporation of Delaware No Drawing. Application June at, 1940, SerialNo. 342,504. In Great Britain July 28, 1939 ZClaims.

This invention relates to improvements in proofing and in particular toa method of fireproofing yarns, fibres, fabrics and other productshaving a basis of cellulose acetate or other organic derivative ofcellulose.

Materials of the kind referred to above are considerably lessinflammable than cotton so that the question of fire-proofing them doesnot normally arise. For certain applications, however, for instance inthe production of theatre curtains and the like and of rugs containingsuch materials,-it is desirable still further to improve theirresistance to fire. This has proved dimcult, primarily since most of theknown fireproofing agents for fabrics are substantially lacking inaffinity for organic derivatives of cellulose.

We have found that materials of the kind referred to above can be givena high degree of resistance to fire by causing them to absorb ahalogenated ester of phosphorus such as tri- (monochlorethyl) phosphatefrom a dispersion of the ester in water or other liquid which is withoutsubstantial swelling action on the materials under the conditions oftreatment.

This fire-proofing treatment does not adversely affect the mechanicalproperties of the materials. It can be carried out simultaneously withdyeing, or can be applied to dyed materials without causing bleeding ofthe dyeings.

The invention may be illustrated with reference to the fire-proofing ofcellulose acetate yarn of heavy denier, e. g. denier of about 5000 ormore, such as is used for the pile of rugs. Such yarn or rugs or carpetscontaining it can be rendered substantially-fire-proof by treatment withan aqueous dispersion of tri-(monochlorethyl) phosphate or likehalogenated ester of phosphorus together with a suitable dispersingagent. The treatment is preferably carried out so that the amount of theester deposited in or on the yarn is from -10%. This can be efiected ina treatment lasting between 3 and 5 hours at a temperature between '75and 80 C. Temperatures in excess of about 78 C. tend to causedelustring. On the other hand, at lower temperatures, for example from20 or 30 up to 50 or 60 C., the operation takes considerably longer.

In baths of the kind referred to above the cellulose derivativematerials may be dyed simultaneously with the fire-proofing treatment bymeans of dispersed insoluble dyes..

The following examples illustrate the invention:

Example 1 A cellulose acetate yarn of denier about 25,000 is immersed inhank form in a bath of the following composition, the parts being byweight:

- Parts Tri-(nionochlorethyl) phosphate 1 A sulphation product of oleylalcohol sold as Cyclanone C. A." 1.5 Pine 0.5 Water 200 By pine oil ismeant an oil obtainable from pine-trees and of which the essentialconstituents are terpene alcohols, principally aand B- terpineols.

The volume of the bath is such that the amount of tri- (monochlorethyl)phosphate present is between 20 and 30% on the weight of the yarn.

The yarn is kept in the bath at a temperature between '70 and C. untilit has absorbed about 5% of the tri-(monochlorethyl) phosphate. It isthen removed and dried without washing.

Example 2 Parts Tri-(monochlorethyl) phosphate 1 Turkey red oil 2 Soap0.3 Water 300 and the temperature of the bath is maintained at 78-80- C.In this way the yarn is delustred simultaneously with fire-proofing.

The process of the invention has considerable advantages over theintroduction of fire-proofing agents into the spinning solution fromwhich the textile materials are made as well as over the application ofthe fire-proofing agent in solution. In the first case the fire-proofingagents are very readily removed during the subsequent dyeing operation.In the second case the solvents used to dissolve the fire-proofing agentare apt to stiffen the materials treated or otherwise adversely aifecttheir physical properties and/or to cause bleeding oi dyes appliedbefore fireproofing. The retention of the mechanical properties of thematerials when treated according to the invention is of specialimportance when the materials comprise voluminous yarns such as can bemade, for instance, by passing an ordinary yarn through crimpingrollers, by highly twisting the yarn first in one direction and then inthe opposite direction to produce a crimp, and/ or by spinning flatfilament yarn with a content of a plasticiser, e. g. para-dichlorbenzeneand crinkling the material by a hot aqueous treatment, if desired afterconverting it into yarn containing staple fibres, as described in U. S.application S. No. 83,274, filed J1me 3, 1936. The hot aqueous treatmentmay be the fire-proofing treatment of the invention and/or may beeffected so as to modify the lustre of the material. Such voluminousyarns and/or cabled yarns made therefrom are of special utility in theproduction of rugs, carpets and other pile fabrics. The presentinvention is of particular importance in connection with the treatmentof such yarns and fab IlCS.

A further advantage of materials fire-proofed according to the presentinvention is that the fire-proofing is resistant to dry cleaningoperations involving the use of liquids such as petrol, ligroin, carbontetrachloride and perchlorethylene. Naturally such operations reduce thefireproof properties of the material to some extent but a valuabledegree of resistance to fire is retained in the materials of theinvention even after several normal dry cleaning operations with any ofthe liquids specified above.

Instead of tri-(monochlorethyl) phosphate other halogenated alkyl estersof phosphoric acid may be employed, for example tri-(monochlorbutyl)phosphate, the corresponding tribrom esters and aryl and aralkyl estersof phosphorus, halogenated, for example chlorinated, in the and nucleus.Other esters of phosphorus though in general less effective asfire-proofing agents, can be applied by similar methods. Among thesemention may be made of tributyl phosphate, tricresyl phosphate,triphenyl phosphate, triethyl glycol phosphate and ethyl glycol-dicresylphosphate.

Although it is in general preferable to apply the fire-proofing agentindispersion in an aqueout medium suitable non-aqueous media may beemployed instead, for example organic fire-proofing agents, such astriphenyl phosphate, which are insoluble in petroleum hydrocarbons canbe applied in the form of a dispersion in such hydro-;

. nitrocellulose acetate.

chlorethyl) phosphate, a dispersing agent, pine carbons, and dyeing canalso be effected simultaneously with the application of the dispersedfire-proofing agent in a non-aqueous non-solvent therefor. Thus, forexample, water-insoluble azo dyes, water-insoluble dyestuffs of thenitro-diarylamine series, water-insoluble indigoid dyestufls andwater-insoluble dyes of the amino-anthraquinone series, for example1:4-diamino-anthraquinone, 1-amino-4-oxyanthraquinone, 1:4-di-(methylamino) anthraquinone and 1:4 di- (ethanolamino)-5:8dioxy-anthraquinone can be applied in a mixture of benzene or aliquid paraffin hydrocarbon and a carboxylic ester such as ethyl acetateas described in British Patent No. 460,575, the fire-proofing agentbeing dispersed in this mixture.

The invention has been described with particular reference to thefire-proofing and coloration of materials having a basis of celluloseacetate, but materials composed of or containing other derivatives ofcellulose, for example cellulose propionate, cellulose butyrate,cellulose acetate-pro pionate, cellulose acetate-butyrate, ethyl andbenzyl cellulose, can also be treated according to the invention. Thematerials treated may also comprise mixed organic-inorganic esters suchas The process of the invention however does not purport to rendermaterials of nitrocellulose non-inflammable nor is the termfire-proofing even when used of very much less inflammable materialssuch as cellulose acetate to be regarded as necessarily involving acomplete removal from the materials of the capacity to burn.

Having described our invention, what we desire to secure by LettersPatent is: v

1. Process for fire-proofing textile materials having a basis of anorganic derivative of cellulose, which comprises impregnating thematerial with from 5 to 10%, based on the weight of the textilematerial, of a halogenated alkyl ester of phosphorus by immersing saidmaterial in a bath containing a halogenated alkyl ester of phosphorus, adispersing agent. pine oil and water.

2. Process for fire-proofing textile materials having a basis ofcellulose acetate, which comprises impregnating the material with from 5to 10%, based on the weight of the textile material, oftri-(monochlorethyl) phosphate by immersing aid material in a bathcontaining tri-(monooil and water for from 3 to 5 hours at a tem-'perature between to C.

WILLIAM IVAN TAYLOR. HENRY CHARLES OLPIN. KENNE'I'H RONALD HOUSE.

